Boeing Looks To Future Technology Needs In MAX Design

Boeing is preparing for a big shift to advanced satellite navigation systems by adopting 787-style digital displays for the 737 MAX program, which will enable easier upgrades as airlines adapt to evolving air traffic control requirements.

The flight deck upgrade “was an important program decision” made on the advice of the 737 Airline Advisory Board, 737 General Manager and Boeing VP Beverly Wyse said today during a conference call detailing the completion of the MAX program’s “firm concept,” which defines its design and capabilities.

Boeing and CFM in April expect to achieve a design freeze on the centerpiece of the MAX program, the introduction of the fuel-saving CFM Leap-1B engine, following their completion of the basic architecture in September. “We have locked down fan size and stage count,” says Chief Project Engineer Michael Teal.

The Leap-1B development begins with the first engine test expected close to June 2014, followed by a start of flight tests in first quarter 2015. FAR 33 certification of the -1B is expected in the first quarter 2016, providing margin for flight testing in 2016.

Aviation Week has learned those flight tests are set for the second quarter.

Wyse says eight aircraft will be involved in MAX testing, four 737-8s, two -9s and two -7s. Boeing’s model designations follow the basic 737-700/800/900ER that they replace.

Three variants of the Leap’s first two core designs have so far been tested, and three more core designs are expected. “We will be running a Core 4 and Core 5 to look at technology for the future,” says Leap Program Manager Gareth Richards. These cores also will be used to support the GE9X development program for the 777X and evolutionary Leap designs, he says.

Final thrust ratings for the Leap-1B are still open but are expected to be about 28,000 lb., making the powerplant slightly smaller than the 33,000 lb. thrust models CFM is developing for the Leap-1A for the AirbusA320NEO and Leap-1C for the Comac C919. Boeing expects to announce the target thrust “before engine design freeze and before we reach firm configuration on the 737 MAX,” Teal says.

Teal says Boeing’s design team has eliminated a chin bump at the nose-wheel landing gear doors that was previously planned to accommodate a longer retraction mechanism. Using radial tires will help because they take less space than bias-ply tires, he says.

The MAX also will employ a digitally controlled electronic bleed air system from Honeywell that will enable pilots to fine-tune cabin pressurization levels based on the exact number of passengers on board as another fuel-saving measure.

The NG’s mechanical bleed air system is controlled by an on-off switch, but digital controls will enable MAX pilots to save fuel flow based on actual payload requirements, says Carl Esposito, Honeywell’s director of product management.

More important, the displays “set up airlines for the future of air navigation,” he says, because they are easily upgradable for synthetic vision, head-up displays (HUDs) and other system advances. Those upgrades bring higher safety margins for flying in deteriorated weather. Just last week, the Civil Aviation Administration of China approved HUDs for eight main airports and expects to add 58 more by 2015.

Despite its larger size, the “look and feel of the new system” will be similar to the NG’s, Standerski says, enabling the rapid transition for NG pilots to the MAX that airlines want.